Pressure release arrangements, in particular for product processing system

Abstract

A valve ( 61 ) for enabling release of pressurized steam from a pressure vessel has a displaceable closure member ( 67 ) which is maintained in its closed disposition by exposure to the pressure of the steam within the pressure vessel. The closure member ( 67 ) is displaced between its closed disposition and an open disposition by a double-acting actuator ( 69 ), suitably an air-driven piston/cylinder device, the closure member ( 67 ) being preferably mounted at one axial end of a spindle ( 68 ) extending between the closure member ( 67 ) and the actuator ( 69 ). The closure member ( 67 ) is suitably mounted for substantially metal-to-metal contact with a valve seat portion ( 63 ), without interposition of any sealing element, preferably for substantially vertical displacement between its closed and dispositions.

1 - 18 . (canceled)  
   
   
       19 . A valve for enabling release of pressurized steam from a pressure vessel, the valve comprising a displaceable closure member which, in its closed disposition, is maintained in said closed disposition by exposure to the pressure of the steam within the pressure vessel, and the closure member being displaceable from said closed disposition to an open disposition against the pressure of the steam within the pressure vessel for said release of pressurized steam from the pressure vessel.  
   
   
       20 . A valve according to  claim 19 , wherein, in a charged condition of the pressure vessel, the pressure of the steam within the pressure vessel is active to hold the valve in said closed disposition.  
   
   
       21 . A valve according to  claim 19 , wherein the closure member is displaceable between said closed disposition and an open disposition by a double-acting actuator.  
   
   
       22 . A valve according to  claim 21 , wherein said double-acting actuator comprises an air-driven piston/cylinder device.  
   
   
       23 . A valve according to  claim 21 , wherein the closure member is mounted at one axial end of a spindle extending between the closure member and said actuator.  
   
   
       24 . A valve according to  claim 19 , wherein the valve member is mounted for substantially metal-to-metal contact with a valve seat portion, without interposition of any sealing element.  
   
   
       25 . A valve according to  claim 19 , wherein the closure member has a face portion which is interchangeably secured to the remainder of the closure member.  
   
   
       26 . A valve according to  claim 19 , comprising a seat portion for engagement by a face portion of the closure member, the seat portion being interchangeably secured to a valve body portion in the seat region.  
   
   
       27 . A valve according to  claim 19 , wherein the closure member is mounted for substantially vertical displacement between said closed disposition and an open disposition thereof.  
   
   
       28 . A valve according to  claim 19 , wherein the nominal flange size of the valve body at the steam exit side is substantially greater than the nominal flange size of the valve body at the steam entry side.  
   
   
       29 . A product treatment system comprising a valve for enabling release of pressurized steam from a pressure vessel, the valve comprising a displaceable closure member which, in its closed disposition, is maintained in said closed disposition by exposure to the pressure of the steam within the pressure vessel, and the closure member being displaceable from said closed disposition to an open disposition against the pressure of the steam within the pressure vessel for said release of pressurized steam from the pressure vessel, wherein the valve is mounted for release of pressurized steam into an expansion region substantially at the point of entry of steam into said expansion region.  
   
   
       30 . A product treatment system comprising a pressure vessel, an expansion region for receiving pressurised steam discharged from the pressure vessel at the end of a steam treatment phase of said product treatment, and a solids trap, said solids trap being in communication with the expansion region to receive steam at a substantially reduced pressure as compared with the steam pressure on initial entry into the expansion region, along with any entrained solid matter.  
   
   
       31 . A product treatment system according to  claim 30 , wherein a baffle is located in said expansion region between a steam entry point and a discharge duct.  
   
   
       32 . A product treatment system comprising a pressure vessel, an expansion region for receiving pressurised steam discharged from the pressure vessel at the end of a steam treatment phase of said product treatment, and a solids trap, said solids trap being in communication with the expansion region to receive steam at a substantially reduced pressure as compared with the steam pressure on initial entry into the expansion region, along with any entrained solid matter, the system further comprising a valve for enabling release of pressurised steam from a pressure vessel into said expansion region, the valve comprising a displaceable closure member which, in its closed disposition, is maintained in said closed disposition by exposure to the pressure of the steam within the pressure vessel, and the closure member being displaceable from said closed disposition to an open disposition against the pressure of the steam within the pressure vessel for said release of pressurized steam from the pressure vessel.  
   
   
       33 . A product treatment system according to  claim 32 , wherein said solids trap acts in a cyclonic manner.  
   
   
       34 . A product treatment system according to  claim 32 , comprising an exhaust stack communicating between said solids trap and atmosphere, said stack including noise reduction means.  
   
   
       35 . A product treatment system according to  claim 34 , wherein said noise reduction means is defined by a stack region of enlarged cross-section transverse to the direction of exhaust flow, said enlarged cross-sectional region comprising a plurality of spaced-apart perforated plates each disposed tranversely to said direction of exhaust flow.  
   
   
       36 . A product treatment system according to  claim 35 , wherein said pressure vessel is rotatable.  
   
   
       37 . A product treatment system according to  claim 32 , wherein said product treatment comprises steam peeling.  
   
   
       38 . A valve for enabling release of pressurized steam from a pressure vessel, the valve comprising a displaceable closure member which, in its closed disposition, is maintained in said closed disposition by exposure to the pressure of the steam within the pressure vessel, and the closure member being displaceable from said closed disposition to an open disposition against the pressure of the steam within the pressure vessel for said release of pressurized steam from the pressure vessel, wherein the nominal flange size of the valve body at the steam exit side is substantially greater than the nominal flange size of the valve body at the steam entry side.